Shopping carts of the kind commonly in use today typically include an upper basket for receiving goods to be transported to a checkout station and a bottom package tray positioned beneath the basket and supported on the base portion of the shopping cart frame. The bottom tray provides additional transport space and is conveniently used for storing bulkier, heavier items. Though provision of a bottom tray, by providing more transport space, allows customers to increase their purchases and thus theoretically encourages larger sales, it can also lead to significant losses to store owners. Because the tray is not readily observable by the checkout attendant, items placed on the tray are often left unpaid for, resulting in significant losses of sales revenue.
The present invention improves upon that situation by providing a signalling device that can be easily coupled onto an existing shopping cart to detect the presence of articles on the bottom package tray of the cart and to automatically siganl the checkout attendant that merchandise is present on the tray. The present signalling device is also relatively simple in construction and thus can be easily and inexpensively fabricated.
Various signalling systems have been previously proposed, but those systems have not been designed for use with existing shopping carts. They have thus required extensive and expensive modifications to the conventional shopping cart and have typically also involved substantial fabrication costs. One such system described in U.S. Pat. No. 4,327,819 to Coutta involves use of a specially designed plastic tray which replaces the bottom tray of the conventional shopping cart. In the Coutta system, the shopping cart is modified so that the existing bottom tray is either removed completely or overlaid with the specially designed plastic tray.
The present invention improves upon the prior art systems by providing a signalling method and device that can be conveniently used on existing shopping carts without requiring any need for costly modifications. It thus provides a practical, cost-effective system for preventing store losses, which has not heretofore been provided by any of the prior art systems.